JP5628304B2 - Lighting system and method with improved signal-to-noise ratio - Google Patents

Description

  The inventive concept relates to a lighting system, and more particularly, a plurality of lighting fixtures each transmitting an identification code in emitted light, and selecting at least one of the lighting fixtures based on the identification code. The present invention relates to a lighting system having a selection device. Furthermore, a corresponding method is presented.

  Lighting systems having a plurality of lighting fixtures are known, wherein the plurality of lighting fixtures utilize transmission of data from the individual lighting fixtures in the emitted light. WO 2006/079199 is a lighting device that includes a light emitting diode (LED) and is driven, for example, by a pulse width modulated signal (PWM) that modulates a data signal. Furthermore, the sensing means is used to receive a data signal in the light emitted by the LED upon detection of all (or part) of the illumination provided by the LED. The data signal is then extracted from the detected illumination.

  This type of technology has been used more recently in point and control mothods for luminaires. Typically, the portable selection device selects and controls individual luminaires by indicating one or more luminaires and identifying the luminaires with an acquired identification code. The identification code can be included in the luminaire and transmitted to the selection device, for example by modulating the light output from the luminaire in an invisible manner by pulse width modulation (PWM). Can be done. Accordingly, the identification code is modulated on the average light intensity output from the lighting fixture. This allows the selection device to select a luminaire based on an identification code obtained in a directional observation field.

  However, in the system described above, the data is emitted in and detected from emitted light (eg, in the form of an identification code), and there are several problems. When receiving identification codes from a plurality of luminaires, the receiver may receive individual signals for several reasons, for example, low light intensity, obstructing objects in the room or distortion of the modulated signal, etc. Can't be solved.

  An object of the present invention is to solve this problem and provide an improved lighting system and method for selecting a luminaire for such a lighting system.

  According to a first aspect of the present invention, this and other objects are achieved by a lighting system having a plurality of lighting fixtures that transmit an identification code ID in each emitted light. The lighting system further comprises a control unit that identifies at least one luminaire having a nominal drive value that is less than or equal to a minimum preset value or greater than a maximum preset value. . The control unit further sets the drive value of the luminaire thus identified to a predetermined value.

  The gist of the present invention is the recognition that the identification code is implemented in the emitted light as luminance modulation. If the drive signal is too low or too high (corresponding to deeply dimmed brightness and close to maximum light brightness, respectively), the modulation depth available is good for detecting the identification code. It becomes critical in providing a signal to noise ratio. Thus, the lighting system identifies and identifies those luminaires that operate with nominal drive values that are too low or too high to allow reliable and preferably seamless brightness modulation. The driving value of the luminaire is set to a predetermined value. At the predetermined value, the available modulation depth is large enough to achieve a good signal-to-noise ratio for the detection of the code.

  According to an embodiment of the lighting system, the system further comprises a selection device for selecting at least one of the lighting fixtures. The selection is based on the identification code.

  According to an embodiment of the lighting system, the selection device transmits a first initialization command and an optional second initialization command. Upon receiving the first initialization command, all luminaires transmit their identification codes except for at least one of the identified luminaires. The step of setting a nominal drive value of the identified luminaire is performed upon receipt of the second initialization command, and after the setting step, the at least one identified luminaire has its own Transmit the identification code.

  In this way, a first set of luminaire readings that provide reliable signal strength of the identification code is detected by the selection device. After this, a second initialization command is used to improve the transmission / detection quality of the identification code for the identified luminaire that cannot be properly modulated in setting the nominal drive value. Start the configuration. Typically, the number of luminaires identified is small, for example, only a small number (assuming m) of the total number of lamps (assuming N) is less than 10% of the maximum driving value, respectively. Driven with a drive value greater than 90%. Therefore, the probability that the user wants to select one of these is low, i.e. ~ m / N << 1. Thus, for the most part, the user only sends one initialization command.

  According to an embodiment of the lighting system, the minimum and / or maximum settings are set before the selection step.

  A predetermined drive value (and thus the brightness level of the emitted light) can be advantageously set in the selection device either in the commissioning (initial setting) of the luminaire or in a later stage. In the case of a color lamp, it has two or more color channels (colored light sources such as red, green and blue LEDs), and a single color channel uses the predetermined driving value. Can be selected. This, on the one hand, causes a slight shift in the color point of the emitted light, but at the same time limits the overall brightness change of the luminaire.

  According to an embodiment of the lighting system, the minimum and / or maximum setpoint is set during the selection step.

  The dynamic setting of the minimum or maximum value is advantageous, for example, when having a luminaire with a very low driving value close to the off state of the luminaire. This is done by allowing the selection device to initially set a low minimum setpoint, and if a sufficient detection signal is not obtainable by the selection device, the selection device will Increase the minimum setting of the luminaire until there is reliable detection. In this way, a minimal increase in the overall light intensity level of the light emitted from the luminaire is achieved while still providing reliable detection. This reduces the visibility of changes in the lighting of the room during transmission of the identification code. A similar procedure can be implemented to obtain a reliable detection for the lamp near the maximum value.

  According to an embodiment of the lighting system, the predetermined drive values are each a fixed percentage value of the minimum or maximum set value. The predetermined drive value is preferably set to a value that does not substantially deviate from the nominal drive value, so as to minimize any perception of changes in light intensity from the luminaire during the selection step, Thus, before the transmission of the identification code, the driving value of each luminaire that is deeply dimmed is increased, for example, to 10% of the maximum driving value for the luminaire, and the driving of the largest luminaire The value is set to 90% of the maximum driving value for the lighting fixture, for example.

  According to an embodiment of the illumination system, the selection unit adjusts the minimum set value based on a signal to noise ratio for the light detected by the selection device. Accordingly, the drive signal to noise ratio level for light measurement in the selection device is advantageously the minimum of the overall light intensity output (and corresponding to the set drive value) of the identified luminaire. It is used as a means for obtaining limit changes.

  According to an embodiment of the lighting system, after the selection step, the drive value of the identified luminaire slowly returns to the initial value (ie returns over a predetermined time interval). The time during which the selection device is selecting the luminaire is relatively short, typically about 200 ms. Risk that the user perceives a change in light intensity by allowing the drive value (corresponding to the light intensity emitted from the light apparatus) of the identified luminaire to slowly return to the initial value Is reduced.

  According to an embodiment of the illumination system, the nominal drive value corresponds to an average light intensity output.

  Furthermore, according to a second aspect of the present invention, a method for selecting a luminaire from a plurality of luminaires is provided. The method includes the steps of identifying at least one luminaire having a nominal drive value less than or equal to a minimum set value or greater than a maximum set value, transmitting an identification code of emitted light from each luminaire, and Setting a luminance value of the identified luminaire to a predetermined luminance value, detecting the identification code, and selecting a luminaire based on the detected identification code. The second aspect of the present invention can generally have the same features and advantages as the first aspect.

  According to an embodiment of the method, the method further comprises providing a first initialization instruction. In response to the first initialization command, the transmitting step is performed for all luminaires except at least one luminaire. The method further comprises the step of optionally providing a second initialization instruction. In response to the second initialization command, the setting step is performed for the at least one identified luminaire, and the transmitting step is for the at least one identified luminaire. To be implemented.

  According to an embodiment of the method, the method slowly returns the drive value of the identified luminaire to the initial value (ie, returns over a predetermined time interval) after the selecting step.

  These and other aspects, features and advantages of the present invention will become apparent and will be elucidated with reference to the embodiments described hereinafter. It should be noted that the invention relates to all possible combinations of the features listed in the appended claims.

  This and other aspects of the present invention will be described in more detail below with reference to the accompanying drawings showing embodiments of the invention.

1 is an illustration of an embodiment of a lighting system according to the concepts of the present invention. 1 is a schematic block diagram illustrating an embodiment of a lighting system according to the concepts of the present invention. 1 is a schematic block diagram illustrating a lighting fixture in an embodiment of a lighting system according to the concepts of the present invention. FIG. 3 is a schematic block diagram illustrating an embodiment of a selection device according to the inventive concept. FIG. 6 is a graph illustrating average light intensity versus time for an identified luminaire according to an embodiment of the inventive concept. FIG. 6 is a graph illustrating average light intensity versus time for an identified luminaire according to an embodiment of the inventive concept. FIG. 6 is a graph illustrating average light intensity versus time for an identified luminaire according to an embodiment of the inventive concept.

  Embodiments according to the inventive concept will now be described in more detail below with reference to the accompanying drawings, in which certain embodiments of the invention are shown. However, the invention can be implemented in many different forms and should not be construed as limited to the embodiments disclosed herein. Rather, this specification is provided by way of example in order to be consistent and complete and to fully convey the scope of the invention to those skilled in the art. Like numbers refer to the same elements throughout.

  FIG. 1 is a diagram of an embodiment of a lighting system 100 according to the concepts of the present invention. A plurality of lighting fixtures 101a-g are arranged, for example, on a ceiling for indoor lighting, and each lighting fixture transmits a corresponding identification code ID in the emitted light. The user selects the luminaire with the selection device 120 for the purpose of controlling the luminaire in an application specific manner. The selection device 120 can select a lighting fixture from a plurality of lighting fixtures by detecting light emitted from the lighting fixture, and can identify individual lighting fixtures based on these ID codes. In addition, each luminaire has a control unit 130 (or is in communication with the control unit 130), and the control unit 130 corresponds to an average light intensity value that is dimmed close to and deepest, respectively. And) identify luminaires having drive values that are too high or too low and adjust the drive values of these identified luminaires to a predetermined drive value.

  Referring now to FIGS. 2a-c, a lighting system according to the inventive concept will be described in more detail. Illustrative embodiments of the lighting system 200 include a plurality of LED-based lighting fixtures 101a-d. Each of the lighting fixtures 101a-d transmits the identification code IDa-d in the light emitted from the lighting fixture 101a-d. Here, the LED-based luminaires 101a-d use means for pulse width modulation (PWM) to set the brightness of the light emitted from the luminaire in the corresponding electric driver 112. . In general, PWM is controlled by two registers, one controlling the duty cycle of the pulse corresponding to the intensity of light output from the luminaire, and the other register setting the PWM frequency. Both registers can generally be set from firmware located within the control unit 130. If the PWM frequency is higher than a few hundred hertz, this is virtually invisible to the human eye. By assigning a different PWM frequency to every luminaire 101a-d, the selection device 120 comprising the photodetector 121 and the signal processing unit 124 determines from which luminaire 101a-d the light hitting the detector 121 originates. Can be distinguished. Here, the optical sensor 121 is a light flux sensor that measures light luminance. However, still other high performance optical sensors (such as cameras) can be used so that other optical characteristics can also be measured. Furthermore, alternative ways of using the identification code can be made by amplitude modulation, code arrangement, etc. This is well known to those skilled in the art and is considered to be within the scope of the inventive concept.

  Each control unit 130 can be arranged in direct connection with each electrical driver 112 of the luminaire 101 to form an independent unit (see FIG. 2b) or as shown in FIG. 2a. It can also be arranged as a central control unit for all luminaires. In an alternative embodiment, the control unit 130 is arranged in the selection device 120 (see FIG. 2c). This selection device then sends the settings to the corresponding electrical driver 112.

  In addition to the code modulation described above, instead of applying the corresponding PWM frequency to each luminaire, the code is substantially changed by slightly changing the brightness of the light by changing the PWM duty cycle. It can be transmitted in an invisible manner. To implement individual IDs, code division multiple access modulation schemes can be used or enabled, for example, by on / off keying or two-phase modulation. Preferably, the IDs are implemented as orthogonal codes that allow them to be easily identified. Since both of these methods can be implemented by firmware only changes, they are very cheap to implement in existing lighting systems.

  The light sources included in the luminaires 101a-d are based on, for example, light emitting diodes, HID lamps (high intensity discharge), halogen lamps, incandescent lamps and / or fluorescent tube lamps.

  Regardless of whether the control unit 130 is arranged in each luminaire, in the selection device or as a central control unit, the luminaires 101a-d for control of the light output from the luminaires 101a-d. (Wireless or wired). Further, the control unit 130 may include a processing unit 131 and software for controlling illumination from the lighting fixture. The control unit 130 may further be connected to a user interface (not shown) to allow clear programming by the user. Furthermore, the control unit 130 may switch off each light source as a whole by a relay or a semiconductor switch, thereby enabling standby power consumption to be reduced (not shown).

  Furthermore, the selection device 120 is a remote control in this exemplary embodiment. In an alternative embodiment, the selection device may be a stationary device. However, for the sake of simplicity, a remote control is used in the following. The remote controller 120 includes a photodetector 121 as described above, a signal processing unit 124 (ie, a microprocessor), a transmitter 122 that transmits signals to the lighting fixtures 101a-d and / or the control unit 130, and a user input 123. Have. User input 123 can be, for example, a key button, a touch indicator, a means for voice commands, and the like. User input 123 allows the user to enter data, such as data to be used in the lighting system, data indicating that a selection must be performed, and selection data.

  If a luminaire selection is to be performed, the user (or alternatively the firmware in control unit 130 or remote control 130) initiates the selection. The user typically initiates the selection by pressing a selection button on the user input 123. Thereafter, communication between the remote controller 120 and the control unit 130 is performed by a signal (for example, a radio frequency signal, light, or the like). The remote control transmits a signal by means of a transmitter 122 to a corresponding receiver 132 arranged in the control unit 130. Alternatively, if the control unit 130 is arranged in the selection device 120 itself, the receiver 132 is arranged in the luminaire 101a for the purpose of setting the driving value of the luminaire.

  The control unit 130 identifies at least one luminaire 101 having a nominal drive value that is less than or equal to the minimum set value or greater than the maximum set value. The nominal drive value for the luminaire is obtained from the drive setting (eg, selected duty cycle) in the control unit 130, or from measurement of drive current, drive amplitude or current power consumption, setting in the driver 112, etc. Can do. Further, the nominal drive value may be obtained by measuring the main light output brightness of the luminaire, or may be stored in the driver 112 as a result of the selection device or a previous drive setting operation. . If a luminaire having a nominal drive value that meets the identification requirement is identified, the control unit 130 sets the drive value of such identified luminaire to a predetermined drive value. For example, if the luminaire is off or has a very low light intensity output, the control unit sets a high drive value (eg, 10% of the maximum drive value). Similarly, if the luminaire is set to maximum or near maximum brightness, the control unit sets a very low drive value (eg, 90% of the maximum drive value). The drive value is typically a value that guarantees the light intensity value of the luminaire that provides a luminance that allows the identification code ID to be transmitted from the luminaire by modulation of the output light. Preferably, the value is set as close to the nominal driving value as possible so as not to cause a very large change in room lighting.

  Each identification code IDa-d is transmitted in the light emitted from the luminaires 101a-d. The remote controller 120 receives the light from the lighting fixtures 101a-d via the light detector 121, and the detection signal is subjected to signal processing. A selection of a specific lighting fixture can then be performed based on the extracted identification codes IDa-d.

  According to an embodiment of the lighting system, the minimum set value and the maximum set value are set prior to the selecting step, for example as entered by a user, in manufacturing or in commissioning of the lighting system. Can be done.

  In addition, several alternative methods of determining the predetermined drive value can be utilized and are discussed further below.

  In an embodiment of the illumination system, the predetermined driving value is a fixed percentage value of the minimum setting value (for driving values that are too low) and a fixed percentage of the maximum setting value (for driving values that are too high). Is set to the value of Alternatively, the value of this ratio depends on the minimum set value or the maximum set value.

  According to an embodiment of the lighting system, the minimum set value and the maximum set value are set in the selection step. Alternatively, only one of the parameters is set in the step of selecting a luminaire. As an example, the remote controller 120 adaptively instructs the lighting fixture to use a minimum set value. Initially, the remote controller 120 instructs the lighting fixtures 101a-d to use a minimum setting value that is 1% lower than the maximum driving value. If the remote control 120 cannot detect the ID code of a certain luminaire, the remote control sets the minimum set value to 2 until a sufficient signal including the ID code from the expected luminaire is detected. The lighting fixtures 101a-d are instructed so as to increase to%.

  In an embodiment, the remote control 120 adapts the minimum setting value depending on the dominant signal-to-noise ratio (SNR). For example, in the case of a luminaire that is deeply dimmed / near off, the remote control starts with a low minimum setting. If the dominant SNR is too low (because the luminaire is too far away and obstructed, or if the nominal drive value for the luminaire is too low), the remote control 120 will have a specific ID code Commands are sent to the control unit 130 to increase the minimum value of the luminaire until reliable detection of light is achieved. A similar procedure can be followed for a luminaire with almost maximum brightness.

  In the embodiment of the lighting system, the remote controller 120 transmits a first initialization command. For example, the user can press a selection button in the user input 123. In addition to the control unit 130 identifying any luminaire having a drive value that is too high or too low, upon receipt of the first initialization command, all luminaires emit, except for the identified luminaire. Transmits its own identification code in light. The remote control 120 can then select one of these unidentified luminaires. The user can then press the selection button twice, which causes the remote control to send a second initialization command. Upon receiving the second initialization command, the control unit 120 performs a step of setting the drive value of the identified lighting fixture to a predetermined drive value. Thereafter, the identified luminaire transmits its identification code. Thus, the second initialization command allows the user to select a luminaire that should be set to a high or very low nominal drive value only if the user actually wants to do this. As can be used.

  Alternatively, the setting of the drive value of the identified luminaire can be performed by a selection unit 130 that directs the identified luminaire, i.e. having a very low / very high drive output. The identified luminaire completely ignores the first initialization command, but increases / decreases its drive power upon receipt of the second initialization command from the selection unit, respectively.

3a-3c are graphs showing the average light intensity versus time output from the identified luminaires during selection. The upper dashed curve shows the average brightness for the luminaire and initially has a drive value that is too high compared to the maximum set value. The lower solid line shows the average brightness for the luminaire and initially has a drive value that is too low compared to the minimum set value. The maximum and minimum set values are shown as average luminance values I _max and I _min in the figure. In Figure 3a, whether the average luminance value of a luminaire having a too high nominal average luminance value is decreased how the selection time t _s, the average luminance value of a luminaire having a too low nominal average luminance value, selection time transient how are increased in t _s is shown. The selection time _{t s} is typically set in a range of 10-500Ms. Preferably, the selection time is set to about 200 ms, which is short enough to be undetectable by the user, but long enough for reliable detection and selection time. Thereafter, the average brightness is returned to the initial nominal value. This can make the viewer aware of changes in light levels, but is not desirable. In FIG. 3b, the difference between the initial nominal average light brightness and the average brightness set at the selected time is almost unclear. In practice, the average luminance value is set close to I _max and I _min to minimize the perceived change in the average light luminance value. The predetermined drive value may also be selected such that the average luminance value during selection is equal to I _max and I _min , FIG. It shows how a smooth return to the average light brightness value (or drive value corresponding to this average light brightness value) is made possible. The decay period that allows the light intensity value to return to the nominal average light intensity value is typically set in the range of 1 to 5 s, preferably 2 s.

A method for selecting a luminaire from a plurality of luminaires according to the inventive concept comprises:
-Identifying at least one luminaire having a nominal drive value that is less than or equal to a minimum set value or greater than a maximum set value;
-Setting the drive value of the identified luminaire to a predetermined value, transmitting an identification code in the emitted light from each luminaire, and detecting the identification code;
-Selecting a luminaire based on the detection identification code;
Have

  Further, an embodiment of the method includes providing a first initialization instruction. In response to the first initialization command, the step of transmitting is performed for all luminaires except at least one identified luminaire. The method further includes providing a second initialization instruction as an option. In response to a second initialization command, the setting step is performed for at least one identified luminaire, and the transmitting step is performed for the at least one identified luminaire. Is done.

  Further, according to an embodiment, the method comprises a step of slowly returning the drive value of the identified luminaire to its initial value over a predetermined time interval after the selecting step.

  In the above, embodiments of the lighting system and method according to the present invention as defined in the appended claims have been described. These should be considered merely non-limiting examples. As will be appreciated by those skilled in the art, many variations and alternative embodiments are possible within the scope of the present invention.

Claims (11)

A plurality of lighting fixtures for transmitting each identification code in the emitted light,
Identifying at least one luminaire having an initial drive value that is less than or equal to a minimum set value or greater than a maximum set value, and wherein the drive value of the at least one identified luminaire is set to a sufficient predetermined value to provide a reading of reliable identification code, the control unit,
A selection device for selecting at least one of the lighting fixtures based on the identification code;
I have a,
A lighting system , wherein after the selection, the drive value of the at least one identified luminaire returns to an initial drive value over a predetermined time interval . When the selection device transmits a first initialization command to the control unit and receives the first initialization command, all the lighting fixtures except for the at least one identified lighting fixture are identified by an identification code. The lighting system according to claim 1 , wherein The selection device transmits a second initialization command, and when the control unit receives the second initialization command, the control unit sets the driving value to the predetermined value of the identified lighting fixture, The lighting system of claim 2 , wherein after the setting step, the at least one identified luminaire transmits an identification code. The lighting system according to any one of claims 1 to 3 , wherein the minimum set value and the maximum set value are set before the selecting step. The lighting system according to any one of claims 1 to 3 , wherein the minimum setting value and the maximum setting value are set in the selection step. The lighting system according to any one of claims 1 to 5 , wherein each of the predetermined values is a fixed percentage value of the minimum setting value or the maximum setting value. The lighting system according to any one of claims 1 to 6 , wherein the control unit adjusts the minimum set value based on a signal-to-noise ratio related to light detected by the selection device . The initial driving value corresponds to the average light intensity output, illumination system according to any one of claims 1 to 7. A method of selecting a luminaire from a plurality of luminaires,
Identifying at least one luminaire having an initial drive value less than or equal to a minimum set value or greater than a maximum set value;
And setting the predetermined sufficient value to provide a reading of reliable identification code of the at least one identified lighting fixture of the drive values at least one identified lighting fixtures,
Transmitting an identification code in the emitted light from each of the plurality of lighting fixtures;
Detecting the identification code;
Selecting a luminaire based on the detected identification code;
After the step of selecting, causing the drive value of the identified luminaire to return to an initial drive value over a predetermined period of time;
Having a method. Providing a first initialization command, wherein, in response to the first initialization command, the transmitting step is for all lighting fixtures except at least one of the identified lighting fixtures. The method of claim 9 , wherein the method is performed. Providing a second initialization command, wherein in response to the second initialization command, the selecting step is performed with respect to at least one identified luminaire, and the transmitting step is the carried out on at least one identified lighting fixtures the method of claim 1 0.

Images